Multimedia presentation devices that have both audio and visual output are frequently used to provide both entertainment and information to users. While these devices have been well suited to providing output for multiple users or to a single isolated user, they have had limited ability to provide output to a single user who is not isolated. Typically, the sound generated from the speakers and light generated by the video display are broadcast and not limited to a region in close proximity of the intended user. The broadcasting of the sound and the light can have two disadvantages. On one hand, it limits the ability of the intended user to receive output which they do not want others to receive, and on the other hand, the broadcasting of the sound and light may distract and/or disturb others near the user. These problems also make it difficult for multiple users to receive individual outputs from independent devices.
Classically, cathode ray tube (CRT) television receivers have been used for audio visual systems. These receivers are not only energy inefficient, using CRT's to provide the visual output, but are frequently large and heavy, which makes repositioning of the television difficult. As a result, the user is frequently required to adjust his/her position in order to view the television. Small, portable televisions and other audio visual systems have been developed using LCD screens for the visual display; however, these devices typically broadcast the sound. Furthermore, these portable devices are designed to be held by the user or to rest on a horizontal surface, which again may require the user to assume a viewing position which is not comfortable to hold for long periods of time.
The issues of focusing the output to a particular user and allowing the user to view from an arbitrary position are particularly important to users in a hospital setting, where the audio visual device may be needed to provide entertainment for a patient who may need to view the audio visual device while in bed without disturbing another patient in the same room who either requires rest or does not wish to be disturbed by the audio visual presentations being viewed by others in the room.
A somewhat similar problem can occur in computer laboratories and dormitory rooms where there are likely to be multiple computers which, today, frequently have multimedia output including speakers. An attempt to address the problem of providing an audio output to a single user is addressed in U.S. Pat. Nos. 5,742,690 and 5,956,411. These patents teach a personal multimedia speaker system for a personal computer. The multimedia speakers have a linear array of speakers to direct sound to the location of the user. A folded waveguide coupled to the speaker array acts to cancel sound in other directions and improve sound quality. The system of the '690 and '411 patents is designed for use with a desktop computer and the depth of the speakers is not a concern, since it is designed to run the full depth of the computer monitor which can typically be 11 inches to 14 inches. These patents also do not address the issue of limiting the visual output to a single user.
Acoustic waveguides have also been employed to provide improved sound quality for large, traditional televisions, as taught in U.S. Pat. Nos. 5,274,709 and 5,524,062. However, here again the depth of the speakers is not a concern. Similarly, these patents do not address the ability to limit the visual output of the system.
For smaller portable computers, which in part overcome the size problem, the efforts to date have been devoted to improving the stereo bass response, such as taught in U.S. Pat. Nos. 5,550,921 and 5,668,882. These patents have not addressed the issue of directional sound, let alone of providing visual output for only a single user.
The issue of user comfort has been addressed by U.S. Pat. No. 6,104,443, which teaches a suspended television receiver or video monitor. The television receiver of the '443 patent is mounted to a positioning mechanism that allows the user to place the television receiver at a desired location and angle for comfortable viewing. The '443 patent discloses both a flexible gooseneck and a parallel arm structure where the parallel arms are connected to provide a scissor type action as they are adjusted to position the television receiver. While the '443 patent addresses the issue of user comfort, it does not address the issue of providing audio visual output to a single user. A gooseneck makes precisely positioning the television receiver difficult for a user, since the gooseneck can have a large elastic component when bent, which will relax once the user releases the television receiver. Alternatively, the gooseneck may be subject to drooping under the weight of the television receiver as the distance from the base increases. Additionally, a gooseneck is not well suited for readily moving the television receiver between viewing and storage positions. The alternative positioning mechanism taught, using parallel arms, can pinch the user as he/she adjusts the position of the television receiver.
Thus, there is a need for a device which can provide an audio visual output to a single user without such output being readily apparent to others in the vicinity of the user, and particularly for such a device which can be readily positioned to allow the user to receive the audio visual output while assuming a comfortable position.